Slender, white, needlelike crystals of sillimanite with biotite in a biotite-sillimanite-feldspar-magnetite-garnet gneiss. Note the large porphyroblasts of feldspar in this specimen and, on left side as photographed, the grains of red garnet. This is Franklin Mineral Museum specimen FMM-7957 and, like others from this locality, came from the Joe Orosz collection via donation from Sharon Orosz.
Identifier: SIL9a Locality: Edison mines, about 2.6 km southeast of Ogdensburg, in Sparta Township Specimen size: 10.5 x 6.5 x 3 cm Photo credit: Elaine Whetstine
